This reference system can be used to position in Two-way ranging mode (TWR). In this reference setup we have placed 3 anchors above and 3 anchors bellow the flight area, shaped in inverse triangles. This allows to get good accuracy in X, Y and Z. There are measurements of accuracy and precision for this reference system.

This reference system can be used to position in Two-Way Ranging mode (TWR) and Time Difference of Arrival mode (TDoA). In this reference setup we have placed 4 anchors above and 4 anchors bellow the flight area, shaped like a box. Note the numbering of the anchors, this allows to get good accuracy in X, Y and Z.

When starting the Crazyflie in the LPS it should be positioned according to the image below.